Receiving an Ajax Response

After the application sends an Ajax request, it is processed on the server
side, and a response is sent back to the client. As described
earlier, Ajax allows for partial updating of web pages. To enable such partial
updating, JavaServer Faces technology allows for partial processing of the view. The handling of
the response is defined by the render attribute of the f:ajax tag.

Similar to the execute attribute, the render attribute defines which sections of the
page will be updated. The value of a render attribute can be
one or more component id values, one of the keywords @this, @all, @none,
and @form, or an EL expression. In the following example, the render attribute
simply identifies an output component to be displayed when the Ajax action has
successfully completed.

Note - Behind the scenes, once again the jsf.ajax.request() method handles the response. It registers
a response-handling callback when the original request is created. When the response is
sent back to the client, the callback is invoked. This callback automatically updates
the client-side DOM to reflect the rendered response.